Unfortunately, Google Nest does not sell any spare parts. However, sometimes Support (https://support.google.com/googlenest/gethelp) may provide a replacement if you're within the 1 year warranty.
Or a Google Nest Community Specialist in this forum may step in and ask you to fill out a "form".
@Nearleafs just one quick final check in here since activity has slowed down. We'll be locking the thread in the next 24 hours, but if you still need help, I would be happy to keep it open. If there's more we can do, just let me know.
I appreciate the help, Brad and MplsCustomer.